For billions of years, life on Earth consisted solely of microorganisms. These tiny lifeforms laid the groundwork for more complex life to evolve and thrive. Following that example, some are wondering if contaminating Mars with microbes could help to ready the red planet for human colonization. That’s what a recent paper published in the journal FEMS Microbiology Ecology proposes.
It’s a controversial idea, but it does make some sense. “Life as we know it cannot exist without beneficial microorganisms,” paper co-author Jose Lopez of Nova Southeastern University said in a statement. “To survive on barren (and as far as all voyages to date tell us) sterile planets, we will have to take beneficial microbes with us.”
Contaminating another planet with Earth’s microbes is a contentious issue for a few reasons. One, it runs afoul of guidelines that NASA and other space agencies have followed for decades. These strict no contamination rules aren’t just about cleanliness.
Before hardware heads to another planet, moon, or asteroid, it receives a good scrubbing. If there is life out there in the solar system or beyond, it’s most likely itself microbial. Therefore, scientists don’t want false positives popping up because a spacecraft becomes contaminated. Interestingly, it’s happened before.
Moreover, no one really knows what intentionally contaminating another world might lead to. As biologists have seen here on Earth, introducing non-native species to combat other invasive species can have unintended negative consequences. Likewise, planetary biologists can’t predict what might happen to these microbes on other worlds.
Nearly every other body in the solar system is bathed in harmful radiation from the Sun or from gas giants like Jupiter. Most of these bodies also lack the protective atmosphere that Earth has. Again, researchers have seen what can happen to lifeforms on Earth when they’re exposed to radiation or foreign chemical processes.
The final reason is a moral one. Just because we have the ability to colonize (and contaminate) another world, does that give humanity the right to? Human beings don’t exactly have the best track record when it comes to colonization. Nor have we done a good job when it comes to meddling in the fine-tuned affairs of our home planet.
As Futurism pointed out, it all comes down to what the ultimate goal is. If terraforming Mars, and thus turning it into a second Earth, is the goal, then introducing microbes to that end is an intriguing idea. On the other hand, if life arose independently on Mars or elsewhere, keeping it pristine is in the best interest of understanding it.
Still, beyond the long-term goal, there’s a pressing question: Could Earth’s microbes even survive on Mars? The paper proposes that extremophiles, lifeforms that exist in harsh environments here on Earth, would have the best chance at survival.
Recently, extremophiles called tardigrades made headlines. The now-famous “water-bears” crash-landed on the surface of the moon along with Israel’s Beresheet lunar lander.
Including water bears on the spacecraft may not have been a great idea. However, to make the best of a bad situation, the intrepid tardigrades could serve as an experiment to see if extremophiles can survive on other bodies in the solar system. Lopez and his colleagues will no doubt keep a close eye on whether the water bears can weather the radiation-soaked lunar landscape.
The plight of the tardigrades does bring up another question: Can humans and their robot proxies go to other worlds without contaminating them? Lopez and other researchers say no. They argue that humanity should consider just “getting it over with” in the name of colonization.
“Microbial introduction should not be considered accidental but inevitable,” the paper states. “We hypothesize the near impossibility of exploring new planets without carrying and/or delivering any microbial travelers.”
The paper goes on to urge spacefarers like NASA and Elon Musk to lead a “provocative paradigm shift” in space colonization policy. Meanwhile, the team also rightfully urges the utmost caution in moving forward with microbial colonization. “This will take time to prepare, discern,” Lopez said. “We are not advocating a rush to inoculate, but only after rigorous, systematic research on Earth.”